Adding a feature to the smbd

[Richard Sharpe]

At 09:13 PM 1/20/01 +0100, Thomas Langås wrote:
>Hi!

Hi, too ...

Can you get rid of the popen in the code ... It is a security risk ...
There is a safe way to do this that is part of one of the parameters
introduced in 2.0.7, as I recall.

>I've been trying to add a feature I called "enhanced path" to the smb.conf,
>basically this was meant to be a command you specified (for instance a
>shell-script) which, when executed, gave _one_ line of output, and this was
>then treated as path. I only added a few lines of code, but it don't seem to
>work like it should, cause the "enhanced path" option doesn't run. So, this
>is what I did to the samba-code:
>
>(all from loadparam.c)
>This is the diff from the original one:
>495d494
>< static BOOL handle_enhanced_path(char *pszParmValue,char **ptr);
>562d560
><   {"enhanced path",    P_STRING,  P_LOCAL,  &sDefault.szPath,
>handle_enhanced_path,   NULL,
>FLAG_BASIC|FLAG_SHARE|FLAG_PRINT|FLAG_DOS_STRING},
>1338,1339d1335
>< //Don't know is this one is needed...
>< FN_LOCAL_STRING(lp_enhanced_pathname,szPath)
>1938,1976d1933
>< 
><
>/***************************************************************************
><  This routine allows you to define a shell-script/program that returns a
><  string. This string will then be the path used.
><  pszParmValue - Contains the command
><  ptr          - Points to szPath
><  This routine is done by Thomas Langås (tlan at stud.ntnu.no)
><
>***************************************************************************/
>< static BOOL handle_enhanced_path(char *pszParmValue,char **ptr)
>< {
><       pstring output, cmd;
><       FILE *mypipe;
><       int retvalue;
>< 
><       pstrcpy(cmd, pszParmValue);
><       standard_sub_basic(cmd);
>< 
><       if ((mypipe = popen(cmd, "r")) != NULL) {
><               if (fgets(output, sizeof(output), mypipe) != NULL) {
><                       retvalue = pclose(mypipe);
><               } else {
><                       //Just ditch the rest of the output
><                       while (fgets(cmd, sizeof(cmd), mypipe) != NULL) {}
><                       retvalue = pclose(mypipe); 
><               }
>< 
><               if (retvalue != 0) 
><                       DEBUG(0, ("handle_enhanced_path: Command exited
with value %d, it echoed \047%s\047", retvalue, output));
>< 
><               unix_to_dos(output, True);
>< 
><               string_set(ptr, (char *) &output[0]);
><               return(True);
><       } else { //Error
><               DEBUG(0, ("handle_enhanced_path: Failed trying to open
>\047%s\047 as pipe\n", pszParmValue));
><               return(True);
><       }
>< }
>< 
>
>
>And this is a snatch from syslog:
>Jan 20 20:47:49 zebra smbd.tlan[559]: [2001/01/20 20:47:49, 0]
param/loadparm.c:handle_enhanced_path(1964)
>Jan 20 20:47:49 zebra smbd.tlan[559]:   handle_enhanced_path: Command
exited with value -1, it echoed '%H/.profil/stud
>
>So, what am I doing wrong? This code get's run each time there's a "path
=" in
>the config, but not when there's a "enhanced path =" instead.
>
>You my ask why I want this, and it's all because we've got several labs
>where I work, and we need different configuration for each lab, and we have
>profiles over samba-shares. So the idea with this was something like this:
>
>[profile]
>  enhanced path = /usr/local/samba/bin/returnpath.sh %I
>
>And, then path should be set to the path returned by that command (which
>would depend on the IP in this case).
>
>-- 
>-Thomas
>
>

Regards
-------
Richard Sharpe, sharpe at ns.aus.com
Samba (Team member, www.samba.org), Ethereal (Team member, www.zing.org)
Contributing author, SAMS Teach Yourself Samba in 24 Hours
Author, Special Edition, Using Samba